<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>

	<body>
		<ul>
			<img src="pic_bulboff.gif" id="myimg">
			<script type="text/javascript">
		
					var myimg = document.getElementById("myimg");
					myimg.onclick=function(){
						if(myimg.src.indexOf('off')!=-1){
							myimg.src="pic_bulbon.gif";
						}else{
							myimg.src="pic_bulboff.gif";
						}
					}
			</script>
		</ul>
	</body>

</html>